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Pine beetle numbers are up across state
MISSISSIPPI STATE -- Mississippi avoided an epidemic of southern pine beetles last year, but a recent survey found epidemic numbers of the beetles in national forests in south Mississippi.
"Last year saw one of the largest outbreaks of southern pine beetles in history," said Glenn Hughes, forestry specialist with Mississippi State University's Extension Service. "Several southeastern states had epidemic populations of southern pine beetles, including Alabama, Tennessee, Georgia, Florida, North and South Carolina, Kentucky and Virginia. Fortunately, Mississippi did not have an epidemic of these beetles in 2001."
This year, trapping surveys conducted in 10 locations indicate southern pine beetle numbers are up in some areas of the state. Aerial surveys have found South Mississippi, especially on the Homochitto National Forest, having the state's worst infestation of southern pine beetles.
"The southern pine beetle populations there are roughly 10 times that of last year," Hughes said. "The increasing population trend, coupled with the high number of southern pine beetles trapped, could spell problems for landowners in this area."
Southeast Mississippi near the DeSoto National Forest has the next highest numbers in the state. The area has an increasing population of pine beetles that are five to six times the numbers seen last year, but even with the increase, the population is moderate, Hughes said.
Based on trappings, central and north Mississippi are predicted to have low population levels this year. With the exception of Oktibbeha County where the population is increasing but low, this area of the state has southern pine beetle populations that are stable or in decline.
"The greatest concern for southern pine beetles, based on this trapping, is in southwest and southeast Mississippi," Hughes said. "Bear in mind that other bark beetles such as ips and black turpentine beetles attack and kill pines, but were not part of this survey."
Hughes said landowners can do several things to protect their forest investment from pine beetle attack. Most importantly is to maintain healthy trees.
"Trees that are healthy are less susceptible to attack," Hughes said. "Thin trees at the right time to keep the stand healthy. If landowners wait too long -- perhaps waiting for pulpwood prices to rebound -- the trees can become unhealthy and more susceptible to bark beetles."
Examine trees, especially during drought, as this stresses trees and makes them more susceptible to attack. Hughes said most landowners first realize there is a problem when pine needles turn from dark green to yellowish-green and then reddish-brown. Once the entire crown begins to change color, the tree is dead.
Also, as the beetles bore into the tree, they leave "pitch tubes," which resemble popcorn or large globs of gum on the tree trunk. Hughes said the beetles can leave hundreds of pitch tubes on a single tree.
"Once your trees are attacked, it is best to remove them as soon as possible. This prevents the mature beetles from leaving the infested tree and moving to nearby, healthy trees," Hughes said. "Generally, trees cannot be saved once the damage is noticed."
While an infested tree in a yard can be individually removed, Hughes said to remove the infested tree and healthy trees in a buffer zone in forested areas. Make the buffer zone as wide as the average tree height in the area.
Few chemicals are available for treating bark beetles. Hughes said Dursban and Lindane have been used successfully in the past but are difficult to find today.
For more information on the southern pine beetle, visit the Southern Pine Beetle Internet Control Center at http://whizlab.isis.vt.edu/servlet/sf/spbicc/.